Basement Watchdog Big Combo CONNECT review: replacing an old primary pump and adding outage backup in one install

This is a research-based review, based on manufacturer specs and published data. We do not test products. Figures come from Basement Watchdog's Big Combo CONNECT (model CITS-50) product page and the safety section of its instruction manual, checked November 1, 2026.

Most battery backup systems are added beside a primary pump that is already in the pit. A combo replaces both. The CITS-50 ships with a 1/2 HP AC primary pump, a 12 V DC backup pump, a controller and charger, two check valves and a Y adaptor that joins both pumps into one discharge. Basement Watchdog describes it as preassembled.

That approach suits a pit with an old or noisy primary pump. Replacing the primary and adding a backup in one job means one set of plumbing cuts and pumps that were sized to fit together. The trade-off is that you replace a primary that may still have life in it, and the controller reports fewer faults than Basement Watchdog's backup-only Big Dog CONNECT.

Who should buy it

• Owners whose primary pump is old, loud or cycling oddly, and who would replace it within a year or two anyway.
• Homes with a 1/2 HP class primary need: 3,540 GPH at 10 ft covers most residential pits with room to spare.
• Households that want the option of a second battery. The parallel jumper cable (sold separately) doubles the maker's runtime figure to 96 hours.
• Homes with a monitored security system: the controller has a remote terminal for a dry-contact device.

Who should skip it

• Anyone with a healthy primary pump. A backup-only unit such as the Big Dog CONNECT keeps the pump you have.
• Homes that want the controller to report a failed backup pump. Basement Watchdog lists that alert as absent on this model.
• Owners who want the longest warranty in a combo. The Wayne WSS30V carries 5 years.

Strengths

• Two pumps, one install. Preassembled primary and backup, with two check valves, pipe and a Y adaptor in the box.
• Strong backup flow. 1,850 GPH at 10 ft, above the Wayne WSS30V's 1,680 GPH backup.
• Longer runtime figure than the Big Dog CONNECT. 48 hours on one AGM battery at 10% duty, against 40.
• Expandable. Two batteries in parallel for 96 hours, per Basement Watchdog.
• Remote options. USB port for the BW-WiFi2 module plus a terminal for a security system or other dry-contact device.

Drawbacks

• No backup pump failure alert. Basement Watchdog's own spec table lists it as absent.
• No automatic pump exercise or battery percentage display, both of which the Big Dog CONNECT has.
• Small charger. 1.6 A, against 20 A on the Big Dog CONNECT, so a drained battery takes longer to recover.
• Replaces your primary pump whether or not it needed replacing.
• Battery and Wi-Fi module sold separately.

How it compares

The CITS-50 against the other combo we review and the backup-only Big Dog CONNECT. Figures are from each maker's page.

Using it in a long outage

What the backup carries in an outage

When the grid drops, the 1/2 HP primary stops and the 12 V backup takes over at 1,850 GPH at 10 ft. That is about half the primary's flow, so a pit that keeps the primary running hard in a storm will rise faster on backup. Basement Watchdog's 48 hours at a 10% duty cycle works out to about 4.8 hours of actual pumping, or roughly 8,900 gallons per battery (our arithmetic from the maker's figures). A second battery doubles that.

For outages longer than a day or two, keep the primary pump running instead. A 1/2 HP pump is a modest generator load: Champion's wattage chart lists 800 to 1,050 running watts and 1,300 to 2,150 starting watts for a 1/2 HP sump pump. Our best generator for a power outage guide shows the sizing, and the backup's 1.6 A charger can run from the same generator.

Covering the alerts it lacks

1. 01Every few months, unplug the primary and pour water into the pit until the backup starts. The CITS-50 does not run its own pump check.
2. 02Look at the controller during that run: if the backup does not start, there is no failure alarm to tell you later.
3. 03Add the BW-WiFi2 module if the house is often empty, so a running backup reaches your phone.
4. 04Write the battery's install date on its case.

A combo install means removing the old pump, cutting the discharge and fitting the new assembly. If that is unfamiliar, a plumber is worth the cost, and an electrician should add any new outlet near the pit.